The present invention relates to a motor vehicle wheel suspension having wheel suspension links and a torsion bar suspension.
In a text by Reimpell, Jörnsen (1st Edition, 1986), p. 307, a rear axle for a motor vehicle is shown having short torsion bars interactingly connected with a wheel suspension. Specifically, the rear axle of Renault Models 9 and 11 with short torsion bars and a screwed-on stabilizer is illustrated (Illustration 7.4/2). As described therein, the accommodation of longer bars is more difficult, which bars are required when the suspension is soft and the travels are large. This relates to the older Renault models 4 and 5 Le Car (as well as the earlier constructions 6, 14 and 16, which had low spring rates of ch=10.5 N/mm and travels of up to sg=287 mm. Renault places the bars behind one another and accepts a wheel base which is different on the left and on the right (Illustrations 7.4/2 to 7.4/4)—a simple solution which results in no driving-related disadvantages. Eccentrics at the ends of the torsion bars are used for adjusting the vehicle height—as shown at the right top of Illustration 7.4/2.
In contrast to Renault, as that text discloses the firms of the PSA Group have retained long bars extending to the other vehicle side. For reasons of accommodation and because of the higher swing center in the case of the “City-Laster”, Talbot provides crossed torsion bars (illustrated in the “Steering” volume).
An object of the present invention is to provide a wheel suspension having a torsion bar spring so that a different wheel spring rate can be achieved.
According to the present invention, this object has been achieved by a torsion bar spring which is oriented to the longitudinal direction of the vehicle and is supported in bearings on the vehicle body, is connected by way of an angle lever fastened to the torsion bar spring with a pressure rod held at the wheel carrier in an articulated manner and extending in the transverse direction of the vehicle, and the torsion bar spring has an adjusting device held at the free end, which adjusting device interacts with a spring element.
Among the principal advantages achieved with the present invention are that, at low loads, that is, during rebounding operations, two connected springs are used, specifically a torsion bar spring and a spring element, such as a coil spring connected behind one another. At higher loads, i.e., during compression operations, the spring element is bridged by an adjusting device, and only the torsion bar spring is still operative. This is achieved through a torsion bar spring, which is oriented in the longitudinal direction of the vehicle and is supported in bearings on the vehicle body, being connected by an angle lever with a pressure rod held in an articulated manner on a wheel carrier and extending in the transverse direction of the vehicle. The torsion bar spring has an adjusting device which is held at its free end and which interacts with a spring element.
Furthermore, according to the present invention, the adjusting device comprises an angle lever held on the torsion bar spring. The angle lever is interactingly connected by an adjusting rod with the spring element. The adjusting rod cooperates with a distance sleeve which holds the spring element in position between a sleeve collar and an abutment at the vehicle body. As a result of this arrangement, by way of the pressure rod, which is connected with a wheel carrier in an articulated manner, an adjusting effect is exercised directly on the torsion bar spring and thus also on the adjusting device for the spring element, specifically as a function of wheel deflection operations.
According to the present invention, the spring element is, for example, a coil spring which, during wheel deflection operations, can be adjusted in an elastic position at lower wheel loads at low spring rates to a blocked position at higher wheel loads with high spring rates. As a result of these two possible positions of the spring element with intermediate positions, the spring element can be connected in a simple manner, on one hand, at low wheel loads, as in the case of rebounding operations, and cooperates with the torsion bar spring. On the other hand, at higher wheel loads, as in the case of compression operations, the spring element is disconnected, and only the torsion bar spring can still operate. For this purpose, in the elastic position, the spring element is constructed to be series connected with the torsion bar spring and, in the blocked position, the spring element is deactivated and the distance sleeve is supported at the abutment and the torsion bar spring forms a single spring element.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.